Process of making artificial stone



[Patented Sept. 14,

- KER-BERT memento HAR I -omen LooKPo-R-T, YORKQANDBCEEARLES 35mm Hnnnrsonon ALGER-S Er-Anon, stouoss'rnnsnmn, EnG -ANDJ v I mio sss on iiinixiis ti anium sigma.

no m'awing.

. more clearly, understood,itissaid Pribrto -is invention, finely diVji'ded rock ,inaterial na s beenuniXed with lime, and the mixture i-hen been molded to the ,des'iredishape pressure, dried, andfsubfected to the creasing gals pressure. [Such procedures may sweeter@mmp1e,in theUnited States tent-s No s1 825,088, 927,822,. 898,703, and 995,268, each to T. Thom,

do not insurethe complete conversion of the imeinm carbonate, and n consequence they produce stone Whichis inferior in hardness and durability to. the stone made by the cessnow' to be; disclosed. p According to our invention, on the other hand, We may take finely diyidedfston'e preferably in the forni of dust, mix it with aproportion of lime, say appro iin ately 20% byweig'ht vof,tl 1e stone mater al, w th sufficient Waterflto I form, a' slurry, and 1 press themiXt-ure intoj the desired form," I

p, A suitable pressure such nieteriels, 'would be between, say,jne andztwo tons, to

the square inch. The molded form,iwhich} mey yconta-in. as much as, s 1,y ,v15% by eighflor Water, may be dried "fandfa SH i a ll qu ntit qi a e f m y be a de as bynu k; ly dipping the stone! Thls quantity Olf,

ater will beffound to besuflioient to. insure Va, satisfactory cerbonzttion when the stone is plncednin a scuiteble and ex"; 33. sed to th e -actloni of w carbonic aerd gas tinder .an incr eesing piie re amount of Water present in the sto e onjs ti tutes important feature of this' nvennom-as Wlll' to complete ca bonation; but satis actory ving failure (I and particularly pointed ont in the 'bohetion.

1. the products obtained fromsaidprolures are Well known n the art. But they 4 a A this s efthree, The ges :pressureused cnnbe jer dm, 3, I

' A pis'ncno i mediie'eez' iber 19119232. sen no; 657 5 85.

sure from ann phgric tosey 300 pounds to four hours.

T e h o y the square inch d uring a periodoftwenty- Which-is believed to "govern results canbe obtained, by raising the pres- (iii the carbonation of the, stone I will, be ex-"' planned hereinefter, and the limits oVernsuccess Will? be indicated,

mite cons er I "which s s et'oryiesult's can be obtained.

or emnp'le, it has loee n' found that the sto ne,=if completely dried Without tiny Eddie r-tionel whter 'beinp introduced, Will not carable} latitude 1 exists ithin bone'te at an, Itj-1s Well asce-fteinejd thetthe stonens'press'ed, containing of water, or somewh'atdess, s toofyvet'for'thie pores too much: elog ged, to allow of satistectory can.

.' arbona o wi take place with Wet" or dry stone, if the'temjperature of i the container and of the stone 1S lnexcess of the boilingv point of aiter,

,4.Wi nt il' i flfih is eh bn h wever, sat sfactory carbonationfjcan; be e'ftested, but when: it is desired to efli ect quick results, "great care must be-token Whenrapidly increasing pressures are usedthat'the consequent temperature lof the stone, dueto' chemical reaction Within the mess, does not exceed the limiting temperature beyond .-l

which the reeotion will: not continue. This l m tin tem era re fr i e d, m be th dissoiation temperature of: the acid bicarbonate" present;

tore intportztntz In carrying out our procedure, it is therethe semen be submitted to he pe t ig 'fithe' earbenie and s in t e presence "a' s' mell proportion of Water,

w szhich may bQ Il'lOfSh conveniently iadd ed b dipping; sprinkling the said stone with water uponthe foutside thereof; H .(2) The; t Pr ssu e be iner-i xs d d rin the rocessor arbonation; TIfh 'attthejheatz g neratedb-y the con ers on of th nine t me; bonateshaH e trtct ed durlng thefcourse o f vthfrea ot-ion,

fellows ly converted into carbonate, in accordance with the following equation:

Ca(OH) +CO :CaCO,-{-H O lVe have found it to bea fact, that if no moisture whatever is present, no chemical reaction takes place. If a very small amount of moisture is present, and the gas pressure remains constant, a slowreaction takes I the mass after shaping 1t and 'to'then d1p place, which comes to an. end'before the whole of the lime has been converted. v If the mixture, on the other hand, is saturated with water, or contains more than a certain quantity of water, the reaction comes to an end before thelime is completely converted,

whether the gas pressure is raised or not. But we have also discovered that if the right amount of water is present, and the.

} triX, uniformlydiffused over the whole mass, which thereby becomes hard and stony throughout. I

While we do not wish to limit ourselves to any particular theory, yet we believe the course of the successful reaction is as follower The carbonic acid gas, in the pres ence of'water, forms. aqueous carbonic acid:

' The aqueous carbonic acid, in the presence of an excessof carbonic acid gas, forms, witn hydrated lime, an acid calcium bicarbonate in accordance with the following equation:

This acidbicarbonate of calcium is unstable, and is decomposed into a carbonate with liberation of carbonic acid gas and water in accordance with the following equation:

Ca rico caco +co +rno T 1e completeness of the conversion of the limejinto carbonate seems to depend upon progressively moistening eaclrparticle of lime present in the stony mass, and the ability to submit each moistened particle to carbonic acid gas at such apressure' that the acid bicarbonate canloe formed.

T From the foregoing, it will be clear that the water to initiate the chemical reaction may be provided as above intimated, either by drying the stone thoroughly, and then dipping it in. water, or by spraying water on the stone, or by allowing steam to condense on it, or said stone may be wetted in' any other suitable Way. When once the chemical action has started, the water necessary to carry it on is provided from the lime itself, as is-clear from the above equatrons. That is, each molecule of l me upon conversion into said bicarbonate,surrenders a molecule of water of hydration, and the molecule of water so set free immediately becomes available to carry on the reaction in the presence of an excess of carbonic acid gas. Whenthe whole of the lime has thus been converted into carbonate, the whole of the water of hydration has been liberated. he preferred method of procedure is to dry the same into water, so that there will be a higher concentration of water on the outer surfaces than on the interior of the stone,

for itis found that the reaction then pro- 7 ceeds without difficulty from said outer surfaces throughout the interior of the mass. I lnother words, as above stated, the reaction tends to cause a continuous accumu lationof water within the interstices of the stone, and therefore, if this-water is added to an excess of water already on the interior the stone may be brought prematurely to an end.

Although, as further stated above,we do not limit ourselves to this theory of chemical action, yet it explains satisfactorily why the procedures we have outlined cause the process of convcrting'lime into the carbonate form to be unusually quick and certain. That is, the wetting of the stone to a limited degree insures a vigorouschemical naction on the outside the moment the material is brought into contact with the carbonic acid gas. This vigorous reaction is accompanied by a rapid rise in temperature, which, as is well known, in accordance with of the mass" the process of making general physical laws, tends to oppose the carbonate cannot exist, and for. any given I pressure there exists a particular dissocia; tiontemperature, above which temperature said acid bicarbonate-cannot exist. But on the other hand, if the gas pressure is raised too much, or too suddenly, the'stone may be come so hot that it cracks, due to an intern sified chemical action. To guard against this, it is advantageous to employ some means of cooling this stone, so that the sur plus heat generated maybe dissipated; In other words, the rise in temperature must be kept under careful control, and the temperature must not be so high that it prevents the formation of the acid bicarbonate. .Still lessmust'i the! temperature be al lmved"to crack :the stone; I I,

The necessary control of the manufacture jacket; towels-ample, when the reactiongoes too fast. By adopting these methods of control; the conversion of the lirne'into calcium carbonate may be effected in a shorter time, and With, much greater certainty disclosed,:in=so far as we areyawarea a The stoner'produced bytlns inventlon is far super ior tOIPIlOI products; and maybe readily distinguished' theretrom' with the aid ofnchemica'l ,tes'ts, due to the fact. that substanti-ally' a lli of the-lime present has been converted into: stone; so that; the latter is harder and-more" uniform in character than are zthelsaidprior products. I

lVhere the words stone materialik or words or similar import, are employed, it isnotiintended'to excludethe use of any suitableaggregate capable ofbeingiiboundby the carbonation of lime; i In all of the procedures described the l me, of course beaca'lciuin or a magnesium lime,;an d it is: preferred" that the nnxture of aggret'i v then moistened; all as herembetore stated;

" It :is obvious thatjthose skilled in the art.

may vary thedetails of the process; Without departinga-froin' the spirit of the invention, 7 and'therefore it is not desired to be-limited" to the above disclosures except as maybe require 1" by the: claims.

What: P claimed is:- 1. The process of making an artificial stonewhich consists in mixing stone ma-i terial with water and lime; drying the mass thus produced; wetting with water the dried mass; subjecting the wettedmaterial to the action ot carbonic acid gas; and increasing 1 the pressure of said gas during the period of carbonation. V I

2. The process of making an artificial stone which consists in mixing stone material with water and lime; drying'the mass thus produced; Wetting with water thedried'. mass; subjecting the Wet mass to. a partial vacuum; subjecting the Wetted material to carbonic acid gas; and increasing the" pressure of said gas during the period of carbonation.

3. The process of making an artificial action of carbonic acid gas; increasing the 7 pressure of said gas during the period of nd efii ciency, than by any other method heretofore ate and lime be first dried completely and V 'tening" tn'e dried mass;

carbonation 51 and abstracting a portion of the "heatfevolved during said period; 7 tw'lhe process 0t making an [artificial stone "which consists in mixing stone terial" with, water; and lime; forming the mass thus producedin the desired shape under pressi'ire; dryingjthe formed i'nass; nicisteinng the dr ed mass; and subgecting the moistened mass-to the action ct carbonic 2H "d gas; and inc; asing the pressure of said duringtheperiodof carbonation.

'ihe"process of making an artificial stone Which consists-in mixing stone material WiSltll mass 11150 the desired shape under pressure;

as during the period of carbonation;

stone: which consists in mixing stone material with raterjandfl lime; forming the mass thus producedfin the desired shape under pressure; c ryi ng the formed mass; inoissub ect1ng the i moistened mass to the action of carbonic acic gas un'der"air-increasing"pressure; and

' tater 1 and lime; forming the an 1 dryingthe formed zmss; moisten-ing "thedried mass; subniittiii i thc mass to the ac artificial v iwith water; and lime; rormingthe mass thus produced int-he desired shape underpressure; drying the formed mass; istening the dried mass; subjecting-the Wet mass'to-apartial; vacuum; subjecting the n'io'istened mass to the action of carbonic cid'gas; and increasing the pressure or said abstracting a portion oit'the heatevolvejd during the period or" carbonation. V

8;"The process or making an vartificial stone which consists in mixing stone material with fwater'. and limey forming the mass thus produced in the desired shapeunder pressure; drying the formedmass; mois tening the dried mass; submitting the mass to the actionofcarbonic acid gas; and ab s tracting a portion of, the heat evolved dur ing the period of carbonation.

9. The process ,of making. an artificial stone which consists in preparing 'witlr Water a mass oi .tinely divided stone material containing lime; drying the mass;

moisteningthe outside of the dried mass only; and subjecting the moistened surfaces to the action of carbonic acid gas. p

' 10. The process of making an artificial stone'which consists in preparing. With Water a mass of finely'divided stone material con taming lune; removing water from said mass; adding water to the outside surface only of said mass; and subjecting the vetted surfaces to an increasing pressure of car bonic acid gas. I 11. The process of making an artificial stone which consists in preparingwvith Water a mass of finely divided stonematerial conlime and only of said mass; and subjecting the wetted surfaces to an increasing pressure of carbonic acid gas; maintaining the temperature of said mass below 212 F.

13. The process of making an artificial stone which consists in nre'iarin with Water .1. l D

a mass of finely divided stone material containing liine; removing water from said mass: adding water to the outside surface only of said subjecting the wetted surfaces to an'incre sing pressure of carbonic acid gas; and withdrawing heat from the mass during the reaction.

14. The process of making an artificial stone which consists in preparing a mass of finely divided stone material containing; water; drying said-mass after it has been molced; superficially wetting with water the dried mass; subjec inp; said wetted mass to t e action of carbonic acid gas to carbonate the same; and increasing the pressure of said gasduring the period of carbonation. r

The process of making an artificial stone which consists in preparing a mass of finely divided stone material containing lime and a predetermined limited quantity of water; drying said mass after it has been molded; superficially wetting with Water he dried mass subjecting said Wetted mass to the action of carbonic acid gas to carbonate" the same; and increasing the pressure of said gas during the period of carbonation. v A

16. The process of making an artificial stonewhich consists in preparing a mass of finely divided stone materialcontaining lime and a predetermined limited quantity of water; completely drying said massafter it i carbonate the same; and increasing'the pressure of said gas while controlling the temperature of said mass during the period of HERBERT CHAMPION HARRISON. CHARLES HOLMES HARRISON.

only 

